My AC is terrible

[OburgOrange]

I read post after post about how bad the AC functions in campers. Why is that? Mine barely blows cool air. My sister has the same size camper as me, and she can hang meat in there it’s so cold. It’s an older camper as well. I don’t get it

[NJKris]

When they work, they work pretty well. But they are cheaply made, therefore don't last. RV'ing is apparently a sport of kings and sultans, supported by mountains of cash thrown into it by an increasingly eager 'donor' group.

[Eddie and Catherine]

Originally Posted by OburgOrange

I read post after post about how bad the AC functions in campers. Why is that? Mine barely blows cool air. My sister has the same size camper as me, and she can hang meat in there it’s so cold. It’s an older camper as well. I don’t get it

I don’t know how old your AC is but mine is 6 years old. I just had it serviced and Freon added. It cools really well now. $100

[txredfish]

My AC was very low on freon. My mobil tech would not just fix and add freon. He said he would lose his dealership license from Coleman if he just added freon. No way to add just replace. Cost me $1500.

[Retired JSO]

Originally Posted by Eddie and Catherine

I don’t know how old your AC is but mine is 6 years old. I just had it serviced and Freon added. It cools really well now. $100

I doubt your tech added Freon as most all RV units are sealed having no service ports. One would have to cut the lines, braze service ports, vacuum and totally refill the system. [moderator snipped unfriendly comment]

[MstngLX50]

Originally Posted by Retired JSO

I doubt your tech added Freon as most all RV units are sealed having no service ports. One would have to cut the lines, braze service ports, vacuum and totally refill the system. --moderator snip--

Bullet taps are like $5. I’ve seen them eke out a few more years from a system with a small leak. Not saying it’s legal to fill a leaking system, or recommended, just that a self piercing tap and some refrigerant could have been added for $100.

[TeachTexas]

Check out this fix. I did it on mine and it made a world of difference

https://www.youtube.com/watch?v=rxCljBVi8DU

[NMWildcat]

Originally Posted by Retired JSO

I doubt your tech added Freon as most all RV units are sealed having no service ports. One would have to cut the lines, braze service ports, vacuum and totally refill the system.

I have had techs add ports to two different a/c units over the years to avoid having to replace the entire unit. They worked great until I sold the RV. Was fairly cheap. It does happen.

[nomad297]

One thing about air conditioning that I have never been sure of is related to the difference in the temperature of the cooled air versus the “ambient” air. I have always understood that the cooled air should be somewhere around 20° colder than the “ambient” air, but I have never known if the “ambient” air temperature is measured outside or inside.

For example; if the ambient temperature is measured outside, in the shade on a 100° day, the inside temperature would never get below 80°, but if it is measured inside, the ambient temperature should get colder and colder as the air conditioner is continuously being fed increasingly colder (ambient) return air.

Which is it?

Bruce

[Flybob]

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[NJKris]

Originally Posted by nomad297

One thing about air conditioning that I have never been sure of is related to the difference in the temperature of the cooled air versus the “ambient” air. I have always understood that the cooled air should be somewhere around 20° colder than the “ambient” air, but I have never known if the “ambient” air temperature is measured outside or inside.

For example; if the ambient temperature is measured outside, in the shade on a 100° day, the inside temperature would never get below 80°, but if it is measured inside, the ambient temperature should get colder and colder as the air conditioner is continuously being fed increasingly colder (ambient) return air.

Which is it?

Bruce

That's actually a good question and one I've wondered about as well. I think there are other factors at play as well, like sunlight. My trailer temp will go 12 degrees above outside temp in full sun light without A/C on or any ventilation (used to go 17 higher before I stuffed a skylight pillow up there). Typically AC guys seem to measure the differential between supply and return, so I believe that is what they mean by 'ambient'.

[lucky55616]

We also had our independent RV repair shop add a valve and Freon to our AC about 2 years ago and has worked much better since then.

[5picker]

I'm knocking on as much wood here as possible... I've owned 15+ R/Vs throughout my camping experiences (PUPS, truck campers, motorhomes, TT and 5th wheels) and all my A/C units have worked and cooled without issues.

I don't know that everyone has mechanical issues as much as expectation issues.

The walls of these R/Vs are extremely thin and poorly insulated. Couple that with parking in the direct sun (no shade cover) and you'll believe it isn't working when it really is doing all it was designed to do. Many folks don't use the 'Quick-dump' feature and blow all that hot air in the roof ducts into the R/V, therefore actually RAISING the temperature when they first turn on the A/C.

Many folks also wait too long to turn the A/C on during the day. Don't wait until it's too uncomfortable to start the A/C. If we run ours early, it keeps the temperature during the rest of the day, much lower than if we wait until it already too hot.

Does that mean there isn't issues sometimes?... no... but sometimes it is simply user expectations that can never be met.

[Chazman]

Maybe a silly question, but when was the last time you cleaned your filters?

[Cajunrver]

Run your AC on high for 5 minutes and check the temp of the air coming out of the vent, then check the air temp of the air going into the return vent. Ideally it should be around a 18 degree difference. If it is significantly less, your AC is the problem. If it’s around 18 or better, your AC is ok. Problem is it takes a long time for the wood and furniture to come up to a cool temp after traveling in the hot sun.

[NJKris]

Always better to open all windows/door when hot inside from travelling, turn exhaust fan on, and purge that hot air before attempting to cool with A/C. Same concept as cooling a hot car. You don't just jump in and turn AC on, you open windows while driving to purge most of hot air first while running AC in non-recirculate mode, THEN close windows.

[Larry-NC]

Originally Posted by nomad297

One thing about air conditioning that I have never been sure of is related to the difference in the temperature of the cooled air versus the “ambient” air. I have always understood that the cooled air should be somewhere around 20° colder than the “ambient” air, but I have never known if the “ambient” air temperature is measured outside or inside.

Which is it?

Bruce

Bruce, the 20° drop appears across the evaporator coil. Since an RV refrigerator only draws from the inside (no fresh air blend option), you would take a measurement away from an outlet and compare it to a measurement near an outlet. You would expect to see about a 20° difference.

Originally Posted by nomad297

For example; if the ambient temperature is measured outside, in the shade on a 100° day, the inside temperature would never get below 80°, but if it is measured inside, the ambient temperature should get colder and colder as the air conditioner is continuously being fed increasingly colder (ambient) return air.

Bruce

Exactly. Since the "ambient" is indoors, the cooler it gets, the cooler the maximum achievable temperature is.

Extending your example, if it's 100 F inside the trailer, the outlet temperature would be 80 F. As soon as the temperature drops to 99, the outlet temperature would be 79 F.

This is within a limited range. As the air cools, there's less heat in it to extract. A heat pump is an air conditioner running in reverse. They are not very effective in cold winter temperatures. There's just not enough heat to extract from the (outside) ambient to bring into the house. I seem to recall that when it's near zero the duct outlet temperature is about 70 F (which feels pretty cool in the winter when the room is 65 F and it's blowing on you).

[rlocicero]

We finally had to replace our Coleman after 11 years in a lot of camping. When we ordered the unit we ordered the 15,000 BTU instead of the 13,500 BTU. It made a big difference for cooling.

[D W]

Originally Posted by txredfish

My AC was very low on freon. My mobil tech would not just fix and add freon. He said he would lose his dealership license from Coleman if he just added freon. No way to add just replace. Cost me $1500.

That's either collusion, or the tech would rather be a "dealer" as opposed to a HVAC Tech.

[D W]

Originally Posted by NJKris

When they work, they work pretty well. But they are cheaply made, therefore don't last. RV'ing is apparently a sport of kings and sultans, supported by mountains of cash thrown into it by an increasingly eager 'donor' group.

That's a very prophetic statement